There seems to be some debate over the name of this title. Is it Showcase Presents or, more simply, Showcase? It matters, probably, when you were first introduced to the work. If you came to it in the early-mid 60s, you might well think of it as Showcase Presents. But if you have a longer view of the title, you probably think of it as just Showcase. Early issues were not so regular in the use of the word that came after "Showcase", at times opting for "presenting", and, on one or two occasions, opting for no anteceding word at all.

A bigger controversy might be over the titling system used in this database. Because some issues had multiple stories, we've opted to title each issue by the most prominent words on the cover--that is, the characters (or, less frequently, story type) that appeared inside. Stories, even when there's just one, are listed individually. This will hopefully give consistency to this deliberately chaotic title.

Whatever the naming controversies, though, the importance of Showcase is fairly clear. The Silver Age's Star-Spangled Comics or All-American Comics this 105-issue run served as a testbed for new characters, and, as such, marks the first appearances of dozens of criminals and heroes.
There were actually a planned 106 issues in this series before the "DC Implosion". Issues #105 and #106 were released (black and white only) in the pages of Cancelled Comic Cavalcade (1978) with #105 showcasing Dead Man and #106 showcasing the Creeper.